Research On The Analysis Method Of Uncertainty In Electromagnetic Scattering Characteristics Of Dielectric Targets

In recent years,computational electromagnetics is developing rapidly and has been widely used in various fields.Considering the influence of uncertain factors,accurate and efficient electromagnetic analysis methods have been the focus of researches.In engineering applications,the geometric shape,coating thickness and dielectric parameters of targets are always varying due to uncertain factors such as weather,environment and human factors.And then it will have a deep influence on the electromagnetic scattering characteristics of targets.Thus,it is quite necessary to analyze the influence of uncertain factors on electromagnetic scattering characteristics of targets accurately and efficiently in theory.This paper focuses on analyzing the influence of uncertain factors on targets' electromagnetic scattering characteristics to increase the confidence level by using the method of moment(Mo M).First of all,this paper proposes an uncertainty analysis method based on surface integral equations to analyze dielectric and metal composite targets.This method can analyze the influence of small deformations from target shape and coating thickness.Secondly,another uncertainty analysis method based on thin dielectric sheets(TDS)is also proposed to analyze structures with partial thin coating,single-layer or multi-layer thin coating.By using this method,influences of small deformations from metallic objects with thin dielectric sheets and influences of slight wobble with the coated dielectric parameters are analyzed.To analyze the electromagnetic scattering from objects with uncertain shapes,NURBS geometric modeling is used and the whole shape of the structure is controlled by several control variables.With these control variables used as random variables to describe small deformation from geometric shapes,the random variables can be expressed with basis functions in electromagnetic field integral equations.In this way,the inherent mechanism of electromagnetic scattering from targets with uncertain shapes can be studied with quantitative analysis.To analyze the electromagnetic scattering from targets with uncertain dielectric parameters or uncertain coating thickness,the uncertain parameters related to medium parameters or coating thickness are extracted as random variables and then introduced into electromagnetic field integral equations.And then the inherent mechanism of electromagnetic scattering from targets with uncertain medium parameters or uncertain coating thickness can be studied with quantitative analysis.